As present networks advance rapidly and information distributes quickly, most communication channels of information between people are primarily through the networks. Besides transmitting text information, the networks also can transmit audio information and video information through the rapidly growing network transmission bandwidth and speed, and thus webcam was introduced to the market.
With reference to FIGS. 1 and 2 for an exploded view and a perspective cross-sectional view of a conventional casing of a webcam respectively, the casing comprises a base 6, a lens ring 7 and two doors 8, wherein a shaft hole 62 is formed separately on both sides of the base 6 and a sheath hole 61 is formed between both sides of the base 6, and a ring slot 611 is formed in the sheath hole 61; and the lens ring 7 includes a ring-shaped flange 71, and the lens ring 7 includes a plurality of protruding pillars 72 disposed in a direction towards a side of the base 6, and the ring-shaped flange 71 is disposed in the ring slot 611 and provided for installing the lens ring 7 into the sheath hole 61 of the base 6; and the doors 8 include a penetrating hole 81 formed on a side of the doors 8, and a coupling slot 82 formed on another side of the doors 8, and the protruding pillars 72 are installed in the penetrating holes 81 respectively, such that the lens ring 7 can be turned to open or close the doors 8, so as to adjust the openness of the lens.
However, the lens ring 7 and base 6 of the conventional casing of a webcam are contacted and assembled directly by the ring-shaped flange 71 and ring slot 611, and they are structures in a rigid contact with each other, so that if a user turns the lens ring 7, the user will feel the rough and jerky hand feel, and the application will give an uncomfortable feeling to the user. If the ring-shaped flange 71 of the lens ring 7 and the ring slot 611 in the sheath hole 61 of the base 6 have an insufficient circularity, a rough edge or a deformation, then such uncomfortable hand feel will be more significant when the user turns the lens ring 7.
To turn the lens ring 7 with respect to the base 6 smoothly, the tolerance of the ring-shaped flange 71 of the lens ring 7 and the ring slot 611 of the base 6 must be controlled precisely. A too-small tolerance will tighten the connection between the lens ring 7 and the base 6 which is unfavorable to the turning, and makes the uncomfortable hand feel more significant when the user turns the lens ring 7. A too-large tolerance will loosen the connection between the lens ring 7 and the base 6, and thus the lens ring 7 cannot be fixed to a certain rotational angle. However, a precisely controlled tolerance will increase the manufacturing time and the manufacturing cost in the design and manufacture processes.
Therefore, it is a main subject for the invention to develop a casing of a webcam capable of widening the tolerance to reduce manufacturing costs and providing a better hand feel to users when turning a lens ring.